Hydraulic flood routing in an ephemeral channel: Wadi Mekerra, Algeria

Abstract

Wadis are a vital source of water in most arid and semi-arid countries. Catastrophic flash floods occurring in wadis are a threat to many societies. The Wadi Mekerra basin in the North-West of Algeria represents one of these semi-arid regions the most affected by floods and has been always one of the main concerns of managers in Sidi Bel Abbes province. In this work, we present the main climatic and hydromorphometric features of Wadi Mekerra watershed. We discuss the main factors that cause flooding in the studied catchment. A hydraulic model based on the Runge-Kutta Discontinuous Galerkin (RKDG) finite element scheme and a limited (existing) field data was applied and compared with measured flow data. The objective was to assess whether a reliable hydraulic flood routing model of a Wadi in a semi-arid region could be developed, with limited cross section data supplemented by topographic map information. A comparison between the measured and simulated results shows that the model used is appropriate for determining the flood hydrograph at the outlet of the watercourse.